MAPK8 and cervical carcinoma: C-Jun N-terminal kinase (JNK) is a downstream signal of RhoB, which can directly upregulate the expression level of RhoB and/or increase the levels of GEF and ECT2 to increase the activity of RhoB, thereby phosphorylating JNK, triggering the pro-apoptotic protein Bim and leading to cell death; it has been speculated that there is a positive feedback relationship between them, with RhoB activity stimulating sustained JNK phosphorylation, thereby enhancing cervical cancer cell death through upregulation of RhoB (Chen et al., 2000) (Figure 5B).